Monday, January 08, 2018

POORWILLS: A NOVEL STRATEGY FOR SURVIVING WINTER'S COLD

Hibernation
is one of the more effective strategies temperate animals have
developed to survive winter's cold temperatures and lack of food
resources. Many birds, bats and even insects opt instead for seasonal
migration, exploiting distant habitats during different seasons. A few,
like the Monarch Butterfly (Danaus plexippus)
and the Poorwill (Phalaenoptilus nuttallii) use a combination of the
two. Poorwills, relatives of Nightjars, breed in arid parts of western
North America from southern Canada into northern Mexico; northern
individuals seem to winter in the desert southwest. A number of bird
species use daily torpor to minimize energy loss during cool nights or
brief bad weather. Members of three related orders, the goatsuckers,
hummingbirds and possibly the swifts, all show some abilities at
metabolic adjustment, but none to the degree of the little Poorwill,
which, in addition to its natural tendencies toward torpor, feeds
heavily on beetles, rich in polyunsaturated fats, which remain liquid
and metabolically available at low temperatures. In the laboratory,
Poorwills have been observed sustaining periods of torpor for over 80
days, and in the wild as long as 25 days.

A shallow shelter, open to
the southern sun is selected: a patch of cactus or rock niche to which
the bird develops substantial fidelity. After sundown, the torpid
Poorwill's body temperature begins to fall, until the ambient
temperature reaches 5.5°C, an apparent optimum hibernating level which
the bird tries to maintain. Solar radiation raises the body temperature
daily, presumably allowing the option to forage during warm nights. I
know of no human witnesses to a Poorwill rousing from torpor in the
wild, but I imagine the bird backing out of his shelter to fully bask in
the final evening rays, periodically flapping his wings to elevate his
body temperature. It's not known how severe a winter these birds can
survive, but a sufficient winter insect population, rather than
temperature, is probably the limiting factor._____________________upper: REANIMATION: COMMON POORWILL (2012) acrylic on illustration board 30" x 20"lower: Field sketches of a female Poorwill feeding on darkling beetles, Salt Lake Co., UT June 2014

Sunday, October 22, 2017

IT'S NATIONAL REPTILE AWARENESS DAY

In honor of National Reptile Awareness Day, I'm recycling this old post, "A SERPENT'S TAIL," from January of 2008:

Those of us from certain parts of North America tend to take rattlesnakes for granted, rarely bothering to appreciate how fantastic they really are. They comprise about 50 species, in two unique American pitviper genera, all with tails that are tipped with a series of complex, interlocking, cornified scales, completely unlike anything else known to have been evolved by snakes—until very recently, anyway. These reptiles are not only specialized at their very tips; the musculature of the tail itself is dominated by three pairs of “shaker” muscles, two of which produce lateral, back-and-forth movements, while the third pair applies torsion, drawing the ventral edge of the rattle outward to either side. The fibers of these muscles are rich in mitochondria, sarcoplasmic reticula, capillaries and glycogen, and capable of sustaining the high respiratory levels necessary to vibrate the tail as rapidly as 100 Hz. for as long as an hour at a time. These speeds are comparable to the oscillations of sphingid moth wings. Among vertebrates, only the hummingbirds (family Trochilidae) can vie with the rattlesnakes in this respect.The rattling system's main function is to warn away dangerous animals like predators and large grazing animals, although in some of the small Sistrurus species, it is only audible at close range, and appears to be of little use in this area. I've never witnessed a wild ungulate or carnivore interacting with a rattlesnake, but have many times seen how effective rattling is in deterring domestic analogs like dogs and horses. Whatever the first proto-rattlers used their tails for, they probably enhanced an already existent behavior. Similar tail movements are exhibited in snakes of many species, in many unrelated taxa. Tail-thrashing of various forms can be a prelude to battle or mating, or a means of evading predators. Some fossorial boids like Calabar Pythons (Charina=Calabaria reinhardtii) and Rubber Boas (C. bottae) wave their blunt tails about while hiding their heads (see photograph here). Some elapids, like the Langsdorff's Coralsnake (Micrurus langsdorffii) pictured above, confuse the enemy by moving both ends simultaneously. Many snakes, including some vipers, vibrate the tail defensively. When doing so against dry vegetation, the resulting sound is not unlike a rattler's. Defensive tail-shaking colubrids, like the Common Racer (Coluber constrictor), lack the specialized tail musculature, and cannot sustain the motion more than several seconds, but the tail muscles of the Copperhead (Agkistrodon contortrix), a close cousin of the rattlesnake, have a significantly elevated respiratory capacity. The traditional view of rattler evolution posits that rattles evolved to enhance this behavior, and, since the earliest-known rattlesnake fossils were found in the American Great Plains, it's tempting to visualize the first rattler warding off vast bison herds like in the painting up top. Genetic mapping, though, strongly suggests that rattlesnakes first evolved in America's southeast, severely shaking this attractive theory.

A third form of tail movement is caudal luring (see video here), a not uncommon behavior in vipers and a number of another snake taxa. It is possible that the earliest rattlers drew potential prey within striking distance by writhing and twitching a simple rattling tail appendage. Caudal luring is practiced by some of the earlier mentioned Sistrurus rattlesnakes, particularly the young ones; in fact, in many of the Crotalus spp. as well, the rattle could function more as a caudal lure in neonates, which can't produce sounds until their first shed. Concurrent with the young snakes' diet shift from ectotherms to mammals is the rattle's increased effectiveness as a sounding device, and the fading of bold colors and patterns on the tail. Both caudal luring and defensive tail-shaking are behaviors seen in the Copperhead.

A new species of viper sheds a bit of new light on the subject. Pseudocerastes urarachnoides was described just over a year ago, from two specimens collected in Iran (a pdf is available here). The holotype, an adult male (above, top), was collected in 1968 and deposited in Chicago's Field Museum. At the time, it was identified as a Persian Horned Viper (P. persicus), but its tail bore a strange appendage resembling a small solifugid (below). This was assumed to be a tumor or other aberration, until a second specimen, a young male (above, lower), was collected in 2003.

The tails of both specimens were carefully examined, and confirmed to be normal and uninjured. The assumption is that these structures are caudal luring devices, although so far, nothing is known of the species' behavior, and caudal luring has not to my knowledge been observed in the other two Pseudocerastes spp (--update--a video of the tail appendage can be seen here. The stomach of the paratype contains a partially digested, unidentified passerine bird. Latifi's Snakes of Iran lists P. persicus' diet as consisting of mice and lizards. Since the female P. urarachnoides is unknown, it's anybody's guess whether or not this tail appendage is a sexual characteristic. Both specimens were preserved in formalin, and their tissues were deemed to be unsuitable for molecular analysis. We can only hope that live specimens will be found and observed. If these hopes are realized, surely they will give us insight into the evolution of their distant cousins on the other side of the northern hemisphere, as well as into the nature of all life.
_____________________upper: PRAIRIE SENTINEL--PRAIRIE RATTLESNAKE (2002) acrylic 40" x 15"middle: LANGSDORFF'S CORALSNAKE AND BLUE-CROWNED MOTMOT (2008) acrylic 15" x 20"lower two: Photos of P. urarachnoides taken from BOSTANCHI et al : NEW SPECIES OF PSEUDOCERASTES FROM IRAN. Proceedings of the California Academy of Sciences, ser 4, 57(14): 443-450 figs 1-4, 8-9

Monday, March 06, 2017

HAPPY BIRTHDAY, KOMODO NATIONAL PARK!

Today is the 37th birthday of one of
the world's most interesting and important National Parks, Komodo
National Park in Indonesia's Lesser Sunda Archipelago. In North
America, much has been made lately of the importance of our national
park system in protecting biodiversity, and while it's probably true
that it's our strongest tool for that job, that's less an endorsement
of the parks than an indictment of our success in protecting
biodiversity. With a couple of exceptions, the National Park
tradition in this part of the world is to protect beautiful scenery
rather than hotspots of biodiversity, but in the rest of the world,
it's more common for national parks to take on that job, and Komodo
National Park is one of the best examples of this, and an example in
microcosm of the Sysiphean nature of that task.

Komodo National Park was founded by the
government of Indonesia in 1980 as a continuation of a long effort to
protect the planet's largest lizard, the Komodo Dragon, or Ora
(Varanus komodoensis). Oras were first protected by law in 1915 by
the Sultan of Bima, just three years after Peter Ouwens first
described the species to European science. In 1928 the Colonial Dutch
Government declared the island of Komodo a wilderness reserve, adding
Padar and southern Rinca 10 years later. Today's park spans part of
Nusa Tenggara Timur, in the Sunda chain between the major islands of
Sumbawa and Flores, comprising the entire range of the Ora, outside
of the large and heavily-populated island of Flores: the islands of
Komodo, Padar, Rinca, Gili Motang, and all of the tiny adjacent
islets.

Oras can reach ten feet in length. A
couple of other monitor species can equal this, but those are more
slender, long-tailed animals well under half the weight of an Ora of
similar length. Like practically all members of their family, Oras
are carnivores. Opportunistic generalists, they eat carrion, small
prey like rodents and snakes, and kill mammals as large as Timor Deer
(Cervus timorensis floriensis), Timor Pigs (Sus scrofa
vittatus) and Water Buffalo (Bubalis bubalis). All three
of these large herbivores were introduced by humans: the pigs
probably long ago, the other two in the 19th century, the
buffalo by Floresians and the Deer by the Sultan of Bima, from the
island of Sumbawa. The preeminent Komodo Dragon scholar Walter
Auffenberg surmised that the species originally evolved to feed on
the dwarf elephants Stegodon sondaari and S. florensis
that inhabited the region until a few thousand years ago, and
transferred their techniques to the large newcomers. As far as I
know, reports of Oras preying on the wild horses (Equus caballus)
that the Sultan of Bima introduced to Rinca have yet to be confirmed.

Auffenberg also credited Oras with the
ability to kill prey with a septic bite, a story that has only
recently been debunked. Controversy continues to swarm about the
nature of their bite, which contains complex toxic proteins capable
of inducing hypothermia, paralysis, haemophilia and loss of
consciousness. Oras are capable of stuffing themselves with as much
as 50% of their own weight. Such a meal can sustain them for over a
month. Usually everything but the hair and bones are digested,
ultimately leaving nothing but a dry fecal pellet.

The lizard I'm befriending in the photo
above is a tame one at the Bali Reptile Park. It, like practically
all captive Oras, is descended from a few lizards captured on Flores
in the 1980s. These lizards are distinct from those of other islands,
where they lack the bluish tones. It seems like genetic transmission
across the narrow strait between Flores and Rinca has been minimal,
presumably due to the treacherous currents there. In the late 1980s,
the population on Padar vanished after a wildfire scorched most of
the island, and it's likely that the surviving Oras, unable to find
prey, swam to nearby Rinca. Since the fire, Timor Deer have
recolonized the island, and park officials are considering
translocating Oras back to Padar, a notion I object to, since the
lizards are arboreal for the first two years of their lives. Since
there are not yet many large trees on the island, any experimental
introductees would likely eat their offspring faster than they could
produce them.

The island of Flores is well populated with
humans, although Labuan Bajo is the only town on the western end of
any size. The Oras on this island have been persecuted as
livestock-killers for centuries, and they persist only in a few
rugged areas. In what numbers is anybody's guess, but it's likely
that between 1,000 and 2,000 individuals survive on the island. At
the moment, probably around 1,200 call Komodo home, while 1,000 are
shared between Rinca and Nusa Kode. Fewer than 100 live on the single
arid cone of Gili Motang.

Oras can live as long as 50 years, and
they become sexually mature at 4-5 years of age. Beginning in June,
males, who outnumber females by more than 3:1, become more active,
attempting to domineer and intimidate other males, while seeking,
courting and eventually copulating with females.

The courtship season lasts through
August, and eggs are usually laid a couple of weeks after
fertilization. More often than not, the female selects an
orange-footed Scrubfowl (Megapodius reinwardt) mound as a
nesting site. Like other members of their family, these birds
construct huge piles of sand mixed with leaf litter where their
buried eggs are incubated by the compost. The female Ora guards her
12-30 eggs for four months, until they hatch. From that time on,
they're on their own.

Komodo National Park is mostly
uninhabited by humans; only four villages occur within its
boundaries. Komodo Village (Kampung Komodo) is by far the largest of
these, with around 1,600 inhabitants. Small human settlements have
come and gone over the centuries, but Komodo Village is the biggest
the island has known. It was established early in the 20th
century by the Sultan of Bima as a penal colony. Bugis fisherman from
Sulawesi, drawn to the region's rich fisheries, also settled here
(the Bugis have a long tradition of seamanship; in past centuries,
the region's most feared pirates were of this ethnicity, and European
sailors returned with terrifying stories of them, giving rise to the
term “boogie-man”).

More recently, ethnic Manggarai from
Flores have joined the population, which has exploded from a mere 30
citizens in the 1920s. Culturally, Komodo Village is still closer to
Bima than anywhere else. It is situated across the bay from Loh
Liang, the Park's main ranger station and visitor's center. On the
island of Rinca, two villages, Rinca (settled near the turn of the
20th century) and Kerora (settled in 1955), are each less
than half the size of Komodo. A small eponymous village on the island
of Papagaran completes the list of human habitation, save a handful
of research and ranger stations with part-time populations.

Each village boasts an elementary
school, but college-preparatory studies are out of reach. The
communities are dependent on fishing, which supplies 97% of village
income. Squid, shrimp and milkfish (Chanos chanos) are the
most important quarry, but mantis shrimp, sea cucumber, abalone, and
various groupers, tuna, sharks and billfish have historically been
sought after. Most farming is subsistence-level only, although some
produce is sold in markets, along with some wild products like
Tamarind (Tamarindus indica), a dominant tree on the islands.
A growing number of Komodo Village artisans make their living selling
woodcarvings and other crafts to tourists at Loh Liang.

In 1995, officials of Komodo National
Park, along with the Indonesian Government, local municipalities and
experts from the Nature Conservancy, began hammering out a 25-year
management plan for the Park. This plan, designed to cope with
expanding human populations, both permanent and transient (especially
tourists) while maintaining a viable Ora population and a healthy
Marine environment, began implementation in 2001. Thoughtful and
practical though it is, the plan has met with controversy in
Indonesia as well as abroad. It has been inaccurately criticized by
anti-conservation activists in the USA as a plan foisted on the
Indonesians by western conservationists. One of the most outrageous
smears appeared in the Wall Street Journal article When Good Lizards
Go Bad, where Yaroslav Trofimov manufactured a preposterous theory
that the plan had changed the behavior of Oras, causing them to kill
Humans in the park.

Today, the Oras are in no imminent danger.
Their populations are currently declining, but not to a worrying
degree. Deer, pigs and other dragon food abounds on Komodo and Rinca,
but an unchecked human explosion will doom the dragons. More urgent
is the situation beneath the ocean's surface. This part of Nusa
Tenggara is especially rich. Its vast coral reefs contain crucial
spawning grounds for Napoleon Wrasse (Cheilinus undulatus) and
other fish of great economic importance to the region. The Management
Plan bans a number of destructive and effective fishing methods,
including explosives and poisons, reef gleaning, long lines, gill
nets and demersal (bottom) traps, effectively restricting fishermen
to using hook and line and traditional light nets. It also imposes
catch limits and denies access to grouper and Napoleon Wrasse
spawning grounds. A long list of fish species is proscribed, as are
all marine invertebrates except squid. Some rather Draconian measures
have been taken on land. All immigration has been disallowed; not
even marriage confers a right to residency in the Park. Dogs and cats
have been banned, as have most other domestic animals, save goats and
chickens, and restrictions have been put on use of fresh water. The
gathering of firewood is no longer allowed and the laws prohibiting
hunting of deer, pigs and buffalo are being strictly enforced. It's
the fishing restrictions, though, that have impacted the already
struggling villagers the hardest, and they've caused considerable
anger. There have been shootouts between rangers and fishermen,
resulting in several deaths. Balancing the needs of the burgeoning
villagers and those of the finite ecosystem is difficult, and the
fact that it's being imposed from outside causes real resentments.

For powerful predators adapted to kill
large prey, it's surprising how rare Ora attacks on humans are. The
earliest documented fatality was a 1931 attempted predation on a
14-year-old boy, whose adult companions frightened the lizard off,
but couldn't prevent his death of blood loss. Some years later, an
adult deer hunter who fell ill was left behind by his companions.
They returned to find his lifeless remains partially eaten by Oras. A
similar case in 1974 was the 78-year old Swiss Baron Rudolf von
Rading, who, after climbing ¾ of the way to a summit, decided
against completing the hike, urging his friends to to go on without
him. They returned to the appointed meeting place to find nothing but
his camera and spectacles. The marker above commemorates this spot
(with camera and glasses placed for effect). Another death took place
a year ago in June of 2008, when a 9-year-old boy named Mansur had
the rudest possible interruption of a backwoods bathroom break. As in
the 1931 case, the Ora was chased off by adults, but the boy died
quickly of blood loss. Park officials attempted, but were unable to
track the animal down. This was the fourth confirmed death (all
occurred on Komodo Island) from an Ora, although there have been many
non-lethal bites and unsubstantiated stories (many from Flores), a
good portion of which are probably true. The fact is that Komodo
Dragons are, and always have been a danger to people where the two
coexist, but only a modest one. Their behavior towards humans has not
changed; as always, an attack is unlikely but unpredictable.

Mr. Trofimov's WSJ article made much of
a supposed ancient and mystical Komodo Village rite where Oras were
fed to keep them from attacking. No such custom ever existed. It is
true that legend considers humans and Oras relatives (actually more
like cousins than reincarnations of ancestors), but the ritual
described in the article most likely refers to on-site gutting of
poached deer, for the Management Plan prohibits no other type of
dragon feeding. The goat sacrifices that Trofimov mentions were
staged for tourists in exchange for cash at the site in the photos
above. The top pic shows the observation platform. Behind it is the
famous commode, for which the island was named (okay, that's a
fabrication of my own). The lower photo shows the view from the
platform. The concrete ring was a pool built to attract Oras. A goat
was staked in the clearing behind this pool for the benefit of park
visitors. These sacrifices were discontinued in the '90s as a result
of changing attitudes and the basic understanding that teaching Oras
to associate humans with feeding is a pretty lame idea.

The dilemma of Komodo village is a
microcosm of what we all face. A century and a half ago, Alfred
Russell Wallace traveled this region and marveled at the simplicity
of island ecology. In that simplicity, he could see how organisms
change and adapt, just as Darwin did in the Galápagos.
In the same way it seems painfully obvious to us how limited the good
citizens of Kampung Komodo are by the resources of their little
island.
_____________________(This post is a revised version of my original
refutation of Yaroslav Trofimov's WSJ, which I originally posted in
September, 2008.)

upper: SPARRING KOMODO DRAGONS (2009) oil on
canvas 48" x 72"image #5: photo taken by Steve Derham at Ubud,
Bali, Indonesia. All other photos taken by CPBvK at or near Komodo
Nat'l Park, Indonesia

Sunday, December 18, 2016

DO WE REALLY WANT REGULATIONS CUT?

We've heard a lot lately about
regulations, and unless I miss my guess, we can expect to hear a lot
more over the next year. With that in mind, it's probably a good idea
to think about what exactly we mean by regulations and their various
benefits and liabilities.

Of course, regulations were
originally designed to keep our individual pursuits of happiness from
conflicting with the happiness of others, and that's still their
purpose. We all know the old saw "My right to swing my fist ends
where your nose starts," and regulations should serve to keep
fists and noses separate. As a society's living standard and
population increase, fists and noses come into closer proximity,
meaning that regulations need to be periodically revised to keep up.
But the narrative we hear most about regulations is that they're
obstacles that keep market forces from doing the beneficial things
they do for society. While it's true that in some instances regulations can do that,
they pale in comparison to the real enemy of the 'invisible hand' of
the marketplace, monopolies. Adam Smith, the father of modern
capitalism, understood this very well two centuries ago, and what was
his prescription for discouraging monopolies? Why government
regulation, of course.

While regulations are necessary and can
do very good things, that's not to say we should cherish them all.
The regulations that affect businesses can be sorted into two piles.
The first pile we'll call benevolent regulation. These laws do things
like prohibiting a business from dumping waste solvents into the
community's drinking water. Antitrust laws would go into this pile as well. Benevolent regulations protect a society's common resources
like water, air and biodiversity. They defend citizens from powerful
interests like governments and corporations. They look out for the
interests of future generations against entities that would conspire
to steal from them.

The second pile we can call "red tape"
regulations. Most of us are familiar with these and have felt the
frustration they engender. They're the sort of hoops a business has
to go through that have no readily discernible function. Reasonable
people will argue about which pile certain laws belong in, but we can
all agree that both piles exist.

It's easy to understand the
function of benevolent regulation, but red tape has an important
function as well. It's a very real obstacle to that individual
entrepreneur who's trying to bring a better mousetrap to market, and
keeps him or her from being able to compete on level ground with
Amalgamated Mousetrap Corporation.

It's not a terrible
oversimplification to say that regulations in our first pile protect
the weak from the powerful while the ones in the second pile protect
the powerful from the weak. That's exactly why I'm skeptical when the
powers that be say they're going to cut regulations. I have a pretty
good idea which pile they have their eye on.
_____________________

Thursday, November 19, 2015

JOE HILL: DEAD FOR A CENTURY

On
November 19, 1915, thirty-six-year-old Joe Hill was shot dead by a
firing squad at the Utah State Prison, on a site in what is now
Sugarhouse Park in Salt Lake City. A troubadour of the
robber-baron age, Hill was born Joel Hägglund.
He left his native Sweden in 1902 for the US, working his away across
the country to California, where he joined the Industrial Workers of
the World, or “Wobblies.” He became active in organizing workers
and served as strike secretary for the IWW in San Pedro. He rose to
prominence writing satirical songs for the Wobblies, such as “Casey
Jones the Union Scab,” “The Rebel Girl,” inspired by Elizabeth
Gurley Flynn, and “The Preacher and the Slave,” whose refrain is
still remembered today:

You
will eat bye and bye in that glorious land in the sky Work and
pray, live on hay, you'll get pie in the sky when you die.

Working on the California docks, he befriended Otto Appelquist,
also a Swedish immigrant. In the summer of 1913, he followed
Appelquist to his adopted home of Salt Lake City, where he found work
at the Silver King Mine in Park City.

The
following winter, on January 14, 1914, the Salt Lake City police
arrested Joe Hill for the murder of a grocer and former policeman and
his teenage son. Four nights earlier, two men masked in red bandanas
had entered the store of John G. Morrison and shot him and his son
Arling dead. Hill had been treated that night for a gunshot wound,
one of five such injuries in the city. He claimed that it had been
received in an altercation over a woman, but he refused to say any
more or identify the parties. Police found a red bandana in Hill's
room. Thirteen-year-old Merlin Morrison, witness to the murder of his
father and brother, said that Hill resembled one of the killers. The
prosecution was not able to suggest a motive or place Hill at the
crime scene, but rested their case solely on circumstantial evidence.
In his instructions to the jury, Judge Morris Ritchie called
circumstantial evidence “the proof of such facts and circumstances
connected with or surrounding the...crime,...and if these facts and
circumstances, when considered all together, are sufficient to
satisfy the...jury of the guilt of the defendant beyond a reasonable
doubt, then such evidence is sufficient to authorize a conviction.”
Hill's own behavior was not helpful to his case. He fired his
attorney and argued with the judge over his right to represent
himself. His prominence with the IWW was a liability, and the two
major powers in Salt Lake City at the time, Kennecott Copper and the
LDS Church, wanted to see him convicted. After what can only be seen
in hindsight as an unfair trial, Hill was found guilty. For
nearly a century, the question of Hill's guilt has been an open one.
In his 2011 biography, “The Man Who Never Died,” William M. Adler
further weakened the prosecution's best evidence with documents
pointing to Otto Appelquist and his former fiancée
Hilda Erickson as Hill's mystery shooter and the object of the
dispute, respectively. Adler also produced evidence that the
Morrisons were killed by career criminal Magnus Olson, alias Frank Z.
Wilson, whom police had arrested earlier in the case, but transferred
to Nevada authorities to face a lesser charge.

Wednesday, November 04, 2015

BIRDS OF A FEATHER

In honor of the wintery nip the weather is finally starting to carry, I'm recycling an old post from September 2006.
The temperature in Salt Lake City has yet to drop below 50ºF, but signs of summer's senescence increase daily. Bird migration is well underway, and our least cold-tolerant summer residents, the nighthawks and hummingbirds, are gone. As the sun's increasingly oblique rays approach the horizon, the red and yellow maples and aspens on the surrounding hillsides cast an orange evening glow into the valley. I wasn't struck hard with an awareness of autumn, though, until last night, when I joined a friend for drinks shortly before dusk. As we entered the club, the assiduous squawking of a thousand Common Starlings (Sturnus vulgaris) met us from the interior of an overhead billboard. It's a sound that I know well, and associate strongly with cold weather. For many years, I was obsessed with hawking starlings with Cooper's Hawks (Accipiter cooperi) and, for one season, with a Merlin (Falco columbarius). A major benefit of flocking is evident when watching a raptor chase a group of starlings or other birds. Upon sensing danger, the flock condenses to a nearly solid mass, and appears to move with a singular intention. The skill with which flocking birds can cue each other and fly as one seems supernatural. Unable to snatch an individual from the fluttering swarm, the pursuing predator is reduced to taking swipes at the entity until one bird loses its head and its timing and finds itself alone and vulnerable. The effort needed to take a starling from a flock exceeds that expended on a single bird by a sizable factor.

Starlings aren't alone in their propensity to get close in the winter, in fact, winter flocking is more the rule than the exception. Starlings' fellow immigrants, the English Sparrows (Passer domesticus), are forming similar coalitions in the city, and soon they'll be joined by a host of other flocking species. In summer, Dark-eyed Juncos (Junco hyemalis) are uncommon and inconspicuous solitary birds here, occasionally glimpsed as a single bird flits through high-elevation undergrowth. As soon as cold weather hits, though, flocks of the fat little birds with their executioners' hoods will be ubiquitous throughout the region. In fact, it seems that on the first really cold morning of each year I see my first junco flock, as if winter were dragged right into the yard on their white-edged tails. In my three PinedaleAnticlineposts, I described the impressive winter flocking of Sage Grouse (Centrocercus urophasianus) and Horned Larks (Eremophila alpestris). Clearly, flocks are less susceptible to predation, but why do birds concentrate only in the winter, when food tends to be scarce, and competition more of a concern? Since the days of Aristotle, observers have pondered this question. In the thirteenth century, Frederick II of Hohenstaufen asserted that flocks protected birds from predators on their long migrations. Other writers have pointed to birds like robins (Turdus spp.) and waxwings (Bombycilla spp.) that feed largely on berries in the winter. These foods are abundant where they occur, but can be difficult to locate. A large group of birds stands a better chance of discovering a large lode capable of feeding the whole. Flocks have an advantage not only over predators, but over competitors, as well. Chickadees (Poecile spp.) and other small birds show far more aggression to single conspecifics than to groups.But birds aren't the only creatures that show this behavior. In my Pinedale Anticline posts, I also discussed winter herding of Pronghorns (Antilocapra americana), which is similar to the behavior of cervids. Even tropical deer like the Indonesian Sambar (Cervus timorensis) congregate in small groups during the boreal summer, which is the dry season there—the season when food is most scarce. When I painted The First Phalanx (above), I had read that troops of Mandrills (Mandrillus sphinx) periodically coalesce into large herds led by a coalition of alpha males. I naïvely painted four big males surrounded in a riot of Central African blooms, unaware that these herds form only in the dry season, when such flowering isn't likely. Five years later, I tracked a large herd of the closely related Drill (M. leucophaeus), an easy job, since their fastidious searching of the dry-season forest floor gave the impression that a Zamboni had driven through the jungle. It makes sense that these large monkeys might find it easier to discover populations of mushrooms and small edible animals in large groups, which are also more intimidating to Leopards (Panthera pardus).

All of these benefits, and surely others as well, accrue to the flocks, herds, murders and gaggles, but I think to better understand the problem, the question should be turned on its head. It seems to me that most animals that congregate in winter are better described as gregarious animals that leave the pack to breed. Competition for food may be more severe in the winter or dry season, but even modest competition is too much for inexperienced juveniles. Most creatures are born during the season when foraging is the easiest, but even so, for many species the protection of the flock is less of a benefit than a liability during this crucial period.
_____________________upper: WORKING THE FLOCK--MERLIN & STARLINGS (1988) acrylic 30" x 20"lower: THE FIRST PHALANX--MANDRILLS (1990) acrylic 20" x 30"

Monday, August 03, 2015

WALRUS SOUVENIR

About his piece "Walrus Souvenir," the artist Andrew Krasnow says:

"As president of the United States, George W. Bush pushed for exploratory drilling in the Arctic National Wildlife Refuge. More concerned with the need for energy than the harm it might cause Walrus habitat, President Bush argued for drilling because there were 'scientific uncertainties' around climate change. For the Walrus, however, the episode may harken back to President Chester A. Arthur (ironically known as 'The Walrus,' for sporting the manly mustache popular at the time) who entered office as the Walrus was on the verge of being hunted into extinction for the oil in its flesh that fueled gas lamps.

Walrus Souvenir is a meditation on the uncertain future for the Walrus and for the natural world when confronted with the priorities of Man. As a memento made from Man's own skin, it suggests that the product of his handiwork may one day be mass extinction, not only for the Walrus and for other animal and plant species, but 'humanity' itself, as their fate is closely tied with ours. As John Lennon sang, 'I am he/ as you are he/ as you are me/ and we are all together...I am the Walrus'"